KDSPY vs MerchantWords (2026): which should you pick?
As of Oct 23, 2026, KDSPY grades higher than MerchantWords: 2.2 against 2.0 out of 4.0.
Checked Oct 23, 2026 · graded Oct 23, 2026 by ToolGPA
KDSPY grades higher on value for money. MerchantWords grades higher on features. They get the same grade on the free plan, ease of use and platforms.
Price, platforms and features side by side. The table says where each price was read and when.
KDSPY
Browser extension for Amazon book category and keyword research
MerchantWords
Amazon keyword research from searches made on Amazon marketplaces
Which one is for you
Pick KDSPY if
- Fits if you self-publish and want sales estimates for a category before you pick a book topic
- Works for authors who research while browsing Amazon and would rather pay once
Look elsewhere if
- Not for you if you want to try it first, as there's no trial or free plan, only a 60-day money-back guarantee
- Skip it if you sell anywhere but Amazon, as its data covers 13 Amazon stores and nothing else
- Watch out: it doesn't work on iPads, tablets or phones, only as an extension in a desktop browser
- Tight if you work on more than two computers, as the license covers two devices you own
- Watch out: sales and revenue figures are its own estimates, and the $79 is shown cut from a crossed-out $197 with no end date
Pick MerchantWords if
- Fits if you write Amazon listings and want the phrases shoppers type there
- Works for checking which keywords put a rival's product on Amazon's first page
Look elsewhere if
- Not for you if you want to try before paying, as there's no free plan or trial
- Skip it if you sell on Walmart, eBay or Etsy too, as that data is only a custom report on request
- Tight if you sell in several countries, as Silver covers one; regional data needs Gold at $79
- Watch out: the whole database refreshes every 3 to 4 weeks, so figures can lag
- Pricey if you need every marketplace, at $149 a month for Platinum, or $749 for a team of up to 20
How we grade them
| 2.2GPAKDSPYFair | 2.0GPAMerchantWordsFair | |
|---|---|---|
| Value for money | A$79 once, with unlimited use and future updates, well under a year of this category's $17 middle subscription. The page shows it cut from a crossed-out $197, with no end date, and tax is added where it applies. | CSilver is $35 a month for 500 searches, billed monthly, a little above this category's dearer quarter. It covers one country, and Keyword Multiplier and Emerging Trends need Gold at $79. |
| Free plan and trial | FNothing is free: no free plan and no trial. A 60-day money-back guarantee is the only safety net, and that isn't a trial. | FNothing free. There's no free plan, and MerchantWords' own help center says there's no free trial either. |
| Features | CBreakdowns of 25,000+ Amazon book categories, sales needed to rank, keyword revenue and competition with A-Z suggestions, author lookups, 30-day rank tracking and ChatGPT prompts. It does Amazon book research fully, but that's a smaller job, and sales and revenue are its estimates. | BAmazon search estimates with seasonality, a keyword multiplier, reverse ASIN lookup, page-one products, emerging trends, bulk search and daily product tracking. It covers Amazon keyword research fully, though the whole database refreshes every 3 to 4 weeks. |
| Ease of use | BNo rating on record. It's a browser extension that works on Amazon's own pages as you browse, with no accounts to connect. | BNo rating on record, but the main tool is a search box: type a phrase and read what Amazon shoppers search. Collections and ASIN lookups sit beside it. |
| Platforms and integrations | CAn extension for Chrome, Firefox, Edge, Opera and Brave on a computer, and the site says it doesn't work on iPads, tablets or phones. Its only link elsewhere is prompts it builds for ChatGPT. | CWeb only, with no integrations or API on record. Walmart, eBay or Etsy data is only a custom report on request. |
| Best for | Amazon book research while you browse the store | Amazon keyword research from Amazon searches |
The GPA is the average of the five grades: an A is 4 points, an F is none. The full reasons are on each tool's page: KDSPY and MerchantWords. How we grade
Where they differ
- KDSPY can be bought with a one-time purchase.
At a glance
| KDSPY | MerchantWords | |
|---|---|---|
| Pricing | Paid | Paid |
| Starts at | $79 one-time, plus tax where it applies | $35 per month for 500 searches, billed monthly |
| Free plan | None | None |
| Free trial | None listed | None listed |
| Web | ||
| Browser extension | ||
| Made by | LeadsClick Ltd (trading as Publishing Altitude) | MerchantWords, Inc. |
| Price read from | kdspy.com | merchantwords.com |
| Checked | Oct 23, 2026 | Oct 23, 2026 |
Worth knowing
KDSPY
- It runs only as a browser extension for Chrome, Firefox, Edge, Opera and Brave; the site says it does not work on iPads, tablets or phones.
- Data covers Amazon only: the US, UK, Canada, Germany, Australia, Italy, Spain, France, India, Japan, Mexico, Brazil and Poland stores.
- There is no free trial or free plan, only a 60-day money-back guarantee.
- The license covers up to two devices you own.
MerchantWords
- There is no free plan, and the help center says there is no free trial.
- Silver covers one country only; regional and global data need Gold or Platinum.
- The data is from Amazon only; Walmart, eBay or Etsy data is offered as a custom report on request.
- Search data is collected daily but the whole database is refreshed every 3 to 4 weeks.
Key features
KDSPY
- Category analysis
- Breaks down any of Amazon's 25,000+ Kindle, book and audiobook categories, with each book's key figures and an estimate of what a first-page listing earns.
- Sales needed to rank
- Estimates how many copies a book has to sell in 24 hours to reach positions 1 to 20 in a category.
- Keyword analysis
- Gives a keyword's revenue potential, the number of competing books and how likely a new book is to rank, with A-Z suggestions that export for Amazon Ads.
- Author and publisher lookups
- Summarizes an author's page in one click, with sales rank and projected revenue for each Kindle, paperback, hardcover and audiobook edition.
- Book tracking
- Follows the daily sales rank of any number of books for 30 days and charts their estimated daily and monthly revenue.
- ChatGPT prompts
- KDSPY Insights builds prompts about a category, keyword or competing book to run in ChatGPT, across eleven report types.
MerchantWords
- Classic Search
- Look up a keyword to see phrases that contain it, with estimated Amazon search volume and seasonality, and save them to collections.
- Keyword Multiplier and Explorer
- Keyword Multiplier generates related and complementary keywords from a search; Keyword Explorer is where research is reviewed and edited.
- ASIN Plus
- A reverse ASIN lookup that shows which keywords put your product, or a competitor's, on the first page of Amazon results.
- Page 1 Products
- Shows the top-ranking products for any keyword on the first page of Amazon search, with figures on how crowded the market is.
- Emerging Trends and history
- Emerging Trends lists searches that are new on Amazon, and a history panel charts when a keyword's searches rise and fall.
- Bulk Search and Product Tracker
- Search many keywords or ASINs at once, and track a product's keyword rankings every day.
Plans
KDSPY
KDSPY Pro$79
one-time
Unlimited use, all future updates and a license for two devices. Shown as reduced from a crossed-out $197, with no end date.
MerchantWords
Silver$35
per month for 500 searches, billed monthly
One country's Amazon data and 10 keyword collections, for new sellers. Keyword Multiplier and Emerging Trends are not included.
Gold$79
per month for 1,000 searches, billed monthly
Data for one region, such as North America, 100 keyword collections, and Keyword Multiplier and Emerging Trends.
Platinum$149
per month for unlimited searches, billed monthly
Global data across every marketplace covered and 1,000 keyword collections, for brands, investors and teams.
Enterprise$749
per month for unlimited searches, billed monthly
Up to 20 users, 10,000 collections and every feature, for large teams and agencies. Set up by contacting sales.
Ways to pay less
KDSPY
No public discounts listed.
MerchantWords
- Annual discount
Two months free with annual billing
MerchantWords' help center says an annual subscription gives two months free, for example $790 a year for Gold and $1,490 for Platinum.
Common questions
Which is cheaper, KDSPY or MerchantWords?
As of Oct 23, 2026, KDSPY starts at $79 one-time, plus tax where it applies, and MerchantWords starts at $35 per month for 500 searches, billed monthly.
Which has a free plan, KDSPY or MerchantWords?
As of Oct 23, 2026, neither KDSPY nor MerchantWords has a free plan.
Which platforms do KDSPY and MerchantWords run on?
As of Oct 23, 2026, only KDSPY lists a browser extension and only MerchantWords lists a web app. A platform missing from a listing is one its maker's pages did not mention.
More comparisons
How this page was made
- The verdict at the top follows a fixed rule. When both tools are in the same category and either is in our top three for it, the verdict follows that ranking: the higher-placed tool is our pick. The top three weigh who each tool suits as well as its grades, so a pick can go against the GPA. Otherwise the page does not pick one and says which grades higher: the higher GPA first; on a tie, the one with a free plan, then the one that starts cheaper in dollars a month, counted the same way for both; if they are still level, what the choice depends on.
- The grades are our own, from each tool’s review or report card. The GPA is their average.
- Prices, plans and platforms come from each tool’s listing. The table above says where each price was read and when.
- The differences and the answers to the questions are worked out from those listings.